<p>
  By a result of <span class="name">
Aoki and Ibukiyama</span>
(Simple graded rings of Siegel modular forms, differential operators and Borcherds products. Internat. J. Math. 16 (2005), 249-279, 
<a href="http://www.ams.org/mathscinet-getitem?mr=MR2130626">MR2130626</a>),
  the ring blah blah blah

</p><p>

  There exists a relation between these generators, namely...
</p>
